Add sleep pin ctrl for BT uart, and also change the bias
configuration to match Bluetooth module.
Signed-off-by: satya priya <skakit@xxxxxxxxxxxxxx>
Reviewed-by: Akash Asthana <akashast@xxxxxxxxxxxxxx>
---
Changes in V2:
- This patch adds sleep state for BT UART. Newly added in V2.
Changes in V3:
- Remove "output-high" for TX from both sleep and default states
as it is not required. Configure pull-up for TX in sleep state.
arch/arm64/boot/dts/qcom/sc7180-idp.dts | 54 +++++++++++++++++++++++++++------
1 file changed, 45 insertions(+), 9 deletions(-)
diff --git a/arch/arm64/boot/dts/qcom/sc7180-idp.dts b/arch/arm64/boot/dts/qcom/sc7180-idp.dts
index d8b5507..806f626 100644
--- a/arch/arm64/boot/dts/qcom/sc7180-idp.dts
+++ b/arch/arm64/boot/dts/qcom/sc7180-idp.dts
@@ -473,20 +473,20 @@
&qup_uart3_default {
pinconf-cts {
- /*
- * Configure a pull-down on 38 (CTS) to match the pull of
- * the Bluetooth module.
- */
+ /* Configure no pull on 38 (CTS) to match Bluetooth module */
pins = "gpio38";
- bias-pull-down;
- output-high;
+ bias-disable;
};
pinconf-rts {
- /* We'll drive 39 (RTS), so no pull */
+ /*
+ * Configure pull-down on 39 (RTS). This is needed to avoid a
+ * floating pin which could mislead Bluetooth controller
+ * with UART RFR state (READY/NOT_READY).
+ */
pins = "gpio39";
drive-strength = <2>;
- bias-disable;
+ bias-pull-down;
};
pinconf-tx {
@@ -494,7 +494,43 @@
pins = "gpio40";
drive-strength = <2>;
bias-disable;
- output-high;
+ };
+
+ pinconf-rx {
+ /*
+ * Configure a pull-up on 41 (RX). This is needed to avoid
+ * garbage data when the TX pin of the Bluetooth module is
+ * in tri-state (module powered off or not driving the
+ * signal yet).
+ */
+ pins = "gpio41";
+ bias-pull-up;
+ };
+};
+
+&qup_uart3_sleep {
+ pinconf-cts {
+ /* Configure no-pull on 38 (CTS) to match Bluetooth module */
+ pins = "gpio38";
+ bias-disable;
+ };
+
+ pinconf-rts {
+ /*
+ * Configure pull-down on 39 (RTS). This is needed to avoid a
+ * floating pin which could mislead Bluetooth controller
+ * with UART RFR state (READY/NOT_READY).
+ */
+ pins = "gpio39";
+ drive-strength = <2>;
+ bias-pull-down;
+ };
+
+ pinconf-tx {
+ /* Configure pull-up on 40 (TX) when it isn't actively driven */
+ pins = "gpio40";
+ drive-strength = <2>;
+ bias-pull-up;
};
pinconf-rx {
--
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